Ultra-compact structure in intermediate-luminosity radio quasars: building a sample of standard cosmological rulers and improving the dark energy constraints up to z∼3z\sim 3

In this paper, we present a new compiled milliarcsecond compact radio data set of 120 intermediate-luminosity quasars in the redshift range $0.46< z <2.76$. These quasars show negligible dependence on redshifts and intrinsic luminosity, and thus represents, in the standard model of cosmology, a fixed comoving-length of standard ruler. We implement a new cosmology-independent technique to calibrate the linear size of of this standard ruler as $l_m= 11.03\pm0.25$ pc, which is the typical radius at which AGN jets become opaque at the observed frequency $\nu\sim 2$ GHz. In the framework of flat $\Lambda$CDM model, we find a high value of the matter density parameter, $\Omega_m=0.322^{+0.244}_{-0.141}$, and a low value of the Hubble constant, $H_0=67.6^{+7.8}_{-7.4}\; \rm{kms}^{-1}\rm{Mpc}^{-1}$, which is in excellent agreement with the CMB anisotropy measurements by \textit{Planck}. We obtain ${\Omega_m}=0.309^{+0.215}_{-0.151}$, $w=-0.970^{+0.500}_{-1.730}$ at 68.3% CL for the constant $w$ of a dynamical dark-energy model, which demonstrates no significant deviation from the concordance $\Lambda$CDM model. Consistent fitting results are also obtained for other cosmological models explaining the cosmic acceleration, like Ricci dark energy (RDE) or Dvali-Gabadadze-Porrati (DGP) brane-world scenario. While no significant change in $w$ with redshift is detected, there is still considerable room for evolution in $w$ and the transition redshift at which $w$ departing from -1 is located at $z\sim 2.0$. Our results demonstrate that the method extensively investigated in our work on observational radio quasar data can be used to effectively derive cosmological information. Finally, we find the combination of high-redshift quasars and low-redshift clusters may provide an important source of angular diameter distances, considering the redshift coverage of these two astrophysical probes.Comment: 36 pages, 5 tables, 16 figures, A&A, in pres

Association of glycemic variability and the presence and severity of coronary artery disease in patients with type 2 diabetes

<p>Abstract</p> <p>Background</p> <p>Glucose variability is one of components of the dysglycemia in diabetes and may play an important role in development of diabetic vascular complications. The objective of this study was to assess the relationship between glycemic variability determined by a continuous glucose monitoring (CGM) system and the presence and severity of coronary artery disease (CAD) in patients with type 2 diabetes mellitus (T2DM).</p> <p>Methods</p> <p>In 344 T2DM patients with chest pain, coronary angiography revealed CAD (coronary stenosis ≥ 50% luminal diameter narrowing) in 252 patients and 92 patients without CAD. Gensini score was used to assess the severity of CAD. All participants' CGM parameters and biochemical characteristics were measured at baseline.</p> <p>Results</p> <p>Diabetic patients with CAD were older, and more were male and cigarette smokers compared with the controls. Levels of the mean amplitude of glycemic excursions (MAGE) (3.7 ± 1.4 mmol/L vs. 3.2 ± 1.2 mmol/L, p < 0.001), postprandial glucose excursion (PPGE) (3.9 ± 1.6 mmol/L vs. 3.6 ± 1.4 mmol/L, p = 0.036), serum high-sensitive C-reactive protein (hs-CRP) (10.7 ± 12.4 mg/L vs. 5.8 ± 6.7 mg/L, p < 0.001) and creatinine (Cr) (87 ± 23 mmol/L vs. 77 ± 14 mmol/L, p < 0.001) were significantly higher in patients with CAD than in patients without CAD. Gensini score closely correlated with age, MAGE, PPGE, hemoglobin A_1c(HbA_1c), hs-CRP and total cholesterol (TC). Multivariate analysis indicated that age (p < 0.001), MAGE (p < 0.001), serum levels of HbA_1c(p = 0.022) and hs-CRP (p = 0.005) were independent determinants for Gensini score. Logistic regression analysis revealed that MAGE ≥ 3.4 mmol/L was an independent predictor for CAD. The area under the receiver-operating characteristic curve for MAGE (0.618, p = 0.001) was superior to that for HbA_1c(0.554, p = 0.129).</p> <p>Conclusions</p> <p>The intraday glycemic variability is associated with the presence and severity of CAD in patients with T2DM. Effects of glycemic excursions on vascular complications should not be neglected in diabetes.</p

catena-Poly[[diaqua­[(4-tolyl­sulfan­yl)acetato-κO]cadmium(II)]-μ-4,4′-bipyridine-κ2 N:N′]

The title complex, [Cd(C9H9O2S)2(C10H8N2)(H2O)2]n, has a linear chain structure. The central CdII ion is in a slightly disorted octa­hedral environment, coordinated by two aqua ligands, two (4-tolyl­sulfan­yl)acetate ligands and two bridging 4,4′-bipyridine ligands. The CdII ion lies on a twofold rotation axis. Inter­molecular O—H⋯O hydrogen bonds connect adjacent chains, forming a layer structure. An intramolecular O—H⋯O hydrogen bond is also present

On leptonic width of X(4260)X(4260)

New measurements on cross sections in $e^+e^-\to J/\psi\pi^+\pi^-$, $h_c\pi^+\pi^-$, $D^0D^{*-}\pi^++c.c.$, $\psi(2S)\pi^+\pi^-$, $\omega\chi_{c0}$ and $J/\psi\eta$ channels have been carried out by BESIII, Belle and BABAR collaborations, and also in the $D_s^*\bar D_s^*$ channel. We perform extensive numerical analyses by combining all these data available, together with those in $D\bar D^*$ and $D^*\bar D^*$ channels. Though the latter show no evident peak around $\sqrt{s}=4.230$ GeV, the missing $X(4260)$ is explained as that it is concealed by the interference effects of the well established charmonia $\psi(4040)$, $\psi(4160)$ and $\psi(4415)$. Our analyses reveal that the leptonic decay width of $X(4260)$ ranges from $O(10^2)$ eV to $O(1)$ keV, and hence may be explained in the conventional quark model picture. That is, the $X(4260)$ may well be interpreted as a mixture of $4^3S_1$ and $3^3D_1$ states.Comment: two small mistakes are fixed, figures redrawn, major physical outputs remain unchanged. Version published in EPJ